Centrifugal compressors are used in various types of gas turbine engines, such as turboprop and turboshaft engines for instance. Overall engine requirements exert a motivation for impeller designs to be optimized for lower weight and reduced axial space. Because of this, modern day impellers tend to have thinner back plate support (the back plate being a radially extending portion of the hub which supports the outlet, or exducer, portion of the vanes, and the support being the radially-inner portion thereof). In turn, thinner back plates can lead to a support which is not as rigid, and can thus involve larger axial tip deflections when running at high speeds. To accommodate larger tip deflections, the tip clearance was increased, which lead to poorer aerodynamic performance and operability.
Accordingly, there remains room for improvement in addressing tip axial deflections at the outlet of centrifugal compressor impellers.